The present invention relates generally to machines for shearing pile-type textile fabrics and, more particularly, to the inspection and adjustment of the relative settings of operative components of such machines.
The basic structure and operation of textile fabric shearing machines is well known and has not changed significantly in recent years. Basically, textile shearing machines have a machine frame on which a shear cylinder, typically equipped with a plurality of helically or spirally extending shear blades projecting outwardly from the cylinder periphery, is mounted for driven rotation. A traveling length of a pile or plush textile fabric is trained through the machine about a series of guide rolls and is presented to the rotating periphery of the shear cylinder for cutting of the pile surface of the fabric by passing the fabric over an elongate cloth or fabric rest which extends in a stationary disposition on the machine frame alongside the periphery of the cylinder. An elongate ledger blade is similarly mounted on the frame alongside the cylinder periphery adjacent the fabric rest. The ledger blade has an arcuate surface conforming to the periphery of the cylinder, which surface terminates at a sharpened edge extending in shear cutting relation along the periphery of the cylinder at a close spacing to the fabric rest. In operation, as a pile or plush fabric is passed over the fabric rest, the fabric rest acts to cause the plush or pile surface of the fabric to extend into the nip area between the cutting edge of the ledger blade and the peripheral cutting blades of the shear cylinder so as to be severed to a desired degree determined by the relative spacing and dispositions of the cylinder, ledger blade and fabric rest.
To ensure uniform shearing of the plush or pile surface of the fabric, it is important that the fabric deflecting surface or edge of the cloth rest and the cutting edge of the ledger blade be precisely linear and parallel both to one another and also to the axis of the shear cylinder. Otherwise, the surface of the fabric may be irregularly sheared to differing pile heights, producing second quality fabric or even rendering the fabric totally useless. While conventional shearing machines provide adjustment mechanisms by which the relative dispositions of the shear cylinder, the cloth rest and the ledger blade can be selectively adjusted, the adjustment mechanisms typically are relatively crude and uncalibrated and, further, it is difficult to accomplish uniformity in the relative dispositions of the cylinder, fabric rest and ledger blade across the entire width of the shearing machine.